NZ science: promising molecule could boost vaccines

A molecule identified by a team of Kiwi scientists could offer a new way to help our bodies mount a more effective immune response to vaccines - with potentially fewer side-effects.

March 6, 2018

By: Jamie Morton

A molecule identified by a team of Kiwi scientists could offer a new way to help our bodies mount a more effective immune response to vaccines – with potentially fewer side-effects.

The work, led by Victoria University’s Associate Professor Bridget Stocker, found the molecule – or “adjuvant” – binded strongly with a specific receptor found in normal, healthy cells.

When added to a vaccine, alongside an antigen, the molecule unlocked a powerful cellular immune response to combat harmful bacteria and viruses, tests in mice showed.

Early results showed it could play a role in developing vaccines for chronic infections such as HIV, Group A Streptococcus, tuberculosis and meningitis.

It could also improve existing vaccines, by generating a better, longer-lasting immune response and reducing the need for booster shots.

Stocker said the adjuvant differed from others currently in use, in that it stimulated a specific type of T-cell response, instead of an antibody-only mediated response, which made it useful in eliminating a number of particular pathogens.

That meant, in theory, it could be used for preventative vaccination, such as standard childhood vaccinations, as well as prophylactic vaccinations for fighting cancer.

She planned to investigate the potential use of the adjuvant in combination with different antigens, such as those that come from outside the body – like bacteria – or those that develop within the body when cells malfunctioned.

A further plus with this adjuvant is that it uses a defined molecule to target a specific receptor, leading to a consistent and defined immune response.

“There’s been a shift in recent years in looking at whether more precise vaccines can be developed so there are fewer adverse side-effects, or less inflammation at the local site,” Stocker said.

“So rather than packing everything into a vaccine, including those parts of a pathogen that don’t facilitate the type of immune response that you want, you’re just adding what you need – very specific ingredients that do the job.”

The next step was to test the adjuvant in more specific disease settings by partnering with other collaborators.

“We have a patent on this compound, but we can only take it up to a certain point until you need a partner to help you take it to the next level,” she said.

“Any one group can only progress something so far.”

The new finding came as part of a wider programme exploring ways to switch off dysfunctional immune cells to develop novel cancer therapies, which was supported by a $500,000 Sir Charles Hercus Research Fellowship awarded by the Health Research Council (HRC).

The study itself, just published in the Journal of Medicinal Chemistry, was funded by the HRC and the Royal Society of New Zealand’s Marsden Fund.

“The field of immunology is developing incredibly fast with both better treatments for infectious diseases and cancer, and work like this – focusing on prevention,” HRC chief executive Professor Kath McPherson said.

“New Zealand scientists are at the forefront of some of this work and the HRC is proud to support them, and their work.”